Saturable-core counting apparatus



April 23, 1968 w. A. GEYGER SATURABLECORE COUNTING APPARATUS Filed April 16, 1964 IHHHHHHHH 3 2 l. as Ewmmau M33 William A. Geyger INVENTOR.

CURRENT PULSES ATTORNEY.

United States Patent 3,379,861 SATURABLE-CORE COUNTING APPARATUS William A. Geyger, Takoina Park, Md., assignor to the United States of America as represented by the Secretary of the Navy Filed Apr. 16, 1964, Ser. No. 360,463 1 Claim. (Cl. 235-92) ABSTRACT OF THE DISCLOSURE A counting circuit including a saturable core counting device in which the saturable core is provided with a winding which is connected to a source of electrical voltage pulses. The field coil of an electromagnetic relay is connected in series with the source of pulses and the winding. On the tenth successive pulse applied to the core, the core saturates and the relay is energized. The contacts of the relay are connected to an electromagnetic counter for counting the pulses.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to a saturable reactor counting apparatus and more particularly to a saturable reactor connected to an electromagnetic digital counter in such a manner as to cause the counter to be energized when the core of the saturable reactor becomes saturated.

In this invention, a saturable reactor is utilized in conjunction with an electromagnetic digital counter. The energizing winding of an electromagnetic digital counter is connected to an energizing voltage through the contacts of an electromagnetic relay. The energizing winding of the relay is connected in a series circuit including an energizing winding of the saturable reactor, a switching means, and a source of D-C voltage. The core of the saturable reactor is equipped with a reset winding which is connected to a reset circuit including a battery connected to the reset winding through a second pair of contacts on the relay.

An object of this invention is to provide a counting device employing a saturable reactor.

Another object of this invention is to provide a means for counting every tenth pulse of a source of voltage pulses.

A further object of this invention is to employ a saturable reactor as a frequency divider.

A still further object of this invention is to provide a saturable core with a source of voltage pulses to energize a relay after a predetermined number of pulses have been applied to said saturable core.

A still further object of this invention is to provide a means for activating an electromagnetic counter upon the saturation of a saturable core.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:

FIG. 1 of the drawings illustrates schematically an embodiment of the instant invention; and

FIG. 2 of the drawings illustrates graphically the magnitude of current pulses applied to the saturable reactor of this invention.

Referring now to FIG. 1 of the drawing, an electromagnetic counter 11 has an electromagnet winding 13 which is energized by AC voltage source 15 through contacts 17 and 19 of relay 21. Relay 21 has electromagnet or solenoid winding 23 which is connected to winding 25 of saturable reactor 27 having a saturable core 29. The saturable reactor energizing circuit includes saturating winding 25, relay solenoid winding 23, a D-C voltage source such as battery 31 and electric switching means 33. A resistor 35 may be added to the circuit as shown to limit the amount of energizing current I which flows through winding 25. The electromagnetic counter 11 is provided with a decimal register 37 which advances one unit each time winding 13 is energized by the A-C voltage source 15 when contacts 17 and 19 are closed.

Referring now to FIGS. 1 and 2 for the operation of the counting apparatus of this invention, it may be seen that counter register 37 will be advanced by one unit or number each time winding 23 is energized with sufiicient energy to cause contacts 17 and 19 to close. When the switching means is first closed, a pulse having a current magnitude of about 1 ma. will be applied through winding 25 of saturable reactor 27. The application of the first pulse to the saturable reactor 27 causes the storage of part of the magnetic flux applied to core 29 by current flow through winding 25. As the second, third and further pulses are applied, more flux is stored in the core until at the time of the tenth pulse, the core becomes saturated and the impedance of winding 25 decreases, increasing the current flow in the circuit to about 3 ma. which is more than sufiicient to activate relay 21 causing contacts 17 and 19 to close as well as 18 and 19. When contacts 17 and 19 are closed, the electromagnetic counter is actuated, causing the decimal register to advance one unit. At the same time that the actuation of relay 21 causes contacts 17 and 19 to be closed, contacts 18 and 19 are also closed by actuation of relay 21. The closing of contacts 18 and 19 energizes another external circuit including resistor 41, battery 43, and winding 45 wound on core 29. With this external circuit closed a reset current I flows through winding 45 resetting core 29 of saturable reactor 27 to an unsaturated condition whereupon the saturation level begins building up almost immediately as pulses are applied to winding 25 as switching means 33 is repeatedly closed and opened. This has been accomplished in an embodiment of this invention with the use of a motor operated switch. With such an arrangement, a time period of pulse current application is in the order of 20 milliseconds. A cycle A-C voltage has been applied to winding 25 through a rectifier to provide a pulse duration of approximately 16 milliseconds.

The pulse current for the first eight pulses was approximately 1 ma. in an embodiment of this invention, the ninth pulse having a magnitude of approximately 1.5 ma. and the tenth or firing pulse having a magnitude of approximately 3 ma. These pulse magnitudes are illustrated in FIG. 2 of the drawings. The duration or magnitude of the pulses, or both may be varied according to the parameters of the saturable reactor and the number of pulses desired between firing pulses.

The switching means 33 of FIG. 1 may be a motor driven electrical switch which will provide a constant time duration of the pulses of current applied to the saturating or energizing winding of the saturable reactor 27. Both the voltage source 31 and the switching means 33 may be replaced by a source of D-C voltage pulses or by a source of A-C voltage applied through a rectifier to the saturable reactor.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

3 4 What is claimed as new and desired to be secured by contacts and the reset winding for resetting said core Letters Patent of the United States is: when the relay is energized, and

1 A counting i i i i means connected to said second pair of relay contacts a saturable core having a saturating winding and a for digitally counting the number of actuation P reset Winding 5 References Cited an electromechanical relay having an energizing winding and first and second pair of contacts, UNITED STATES PATENTS a pulse source connected in series with said saturating 2,904,727 9/ 1959 Chen 307-88 winding and said energizing winding for supplying 3,278,918 10/1966 Smith 23592 both saturating pulses to said core and an actuation 10 pulse to said relay when the core becomes saturated, MAYNARD WILBUR Prlmary Exammer' means serially connected between first pair of relay MAIER, Assistant Examine!- 

